An art gallery engages a security guard to ensure that the items displayed are protected. The diagram below represents the plan of the gallery where the boundary walls are opaque. The location the security guard posted is identified such that all the inner space (shaded region in the plan) of the gallery is within the line of sight of the security guard. If the security guard does not move around the posted location and has a 360$$^\circ$$ view, which one of the following correctly represents the set of ALL possible locations among the locations P, Q, R, and S, where the security guard can be posted to watch over the entire inner space of the gallery.

Mosquitoes pose a threat to human health. Controlling mosquitoes using chemicals may have undesired consequences. In Florida, authorities have used genetically modified mosquitoes to control the overall mosquito population. It remains to be seen if this novel approach has unforeseen consequences.

Which one of the following is the correct logical inference based on the information in the above passage?

Consider the following inequalities.

(i) 2x $$-$$ 1 > 7

(ii) 2x $$-$$ 9 < 1

Which one of the following expressions below satisfies the above two inequalities?

Four points P(0, 1), Q(0, $$-$$3), R($$-$$2, $$-$$1), and S(2, $$-$$1) represent the vertices of a quadrilateral. What is the area enclosed by the quadrilateral?